SUMMARY OF THE PRESENT INVENTION
This invention relates to a bicycle, and particularly to a bicycle having jumping capabilities. The invention is an improvement on the invention disclosed in my issued U.S. Pat. No. 5,301,969.
The term "jumping capability" is herein used to reference a construction wherein a spring means is stressed by the action of the person riding the bicycle so that when the person removes the stress the spring means exerts an upward force on the bicycle frame, thereby causing the bicycle to become airborne. The bicycle thus is enabled to jump or leap over obstacles in the path of the bicycle.
In preferred practice of the invention, the bicycle is equipped with a main frame having rotary connections to the front and rear ground wheels, whereby the bicycle can be propelled along the ground in conventional fashion.
The conventional chain-sprocket drive is provided for propulsion purposes; and the usual foot pedals are used to rotate the sprocket. However, the sprocket is rotatably supported on a special auxiliary frame that is floatably mounted on the main frame for up-and-down motion. Spring mechanisms at opposite ends of the main frame resiliently support the auxiliary frame in a raised position.
In order to achieve a jumping action the rider momentarily stops operating the foot pedals and raises his body off the seat so as to apply a large downward force on both foot pedals. The auxiliary frame is thus moved downwardly to stress the spring mechanisms. The person then abruptly transfers his weight back onto the seat while exerting an upward hand force on the handlebars. The stressed spring mechanisms propel the auxiliary frame upwardly against the upper frame. When the auxiliary frame forcibly impacts the main frame, inertia forces cause the main frame to be deflected upwardly, thus causing the bicycle to become airborne.
Further features of the invention will be apparent from the attached drawings and description of an illustrative embodiment of the invention.
In summary, and in accordance with the above discussion, the foregoing objectives are achieved in the following embodiments.
1. A bicycle with jumping capability comprising:
a front road wheel and a rear road wheel; PA1 an upper main frame having rotary connections to said road wheels; PA1 a seat mounted on said upper main frame proximate to the rear road wheel; PA1 a handlebar means rotatably mounted on said upper frame proximate to the front road wheel; PA1 a steering connection between the front road wheel and said handlebar means; PA1 a lower frame floatably mounted on said upper frame for relative upward or downward movement; PA1 a propulsion means that includes a rotary sprocket carried by said lower frame, and a pedal means for operating said sprocket; and PA1 spring means biasing said lower frame upwardly; and stop means limiting upward movement of said lower frame, whereby a person riding the bicycle can exert a downward force on said pedal means to move the lower frame downwardly, after which the person can remove the downward force on said pedal means, so that the lower frame forcibly impacts said stop means to generate an upward lifting force on said upper frame.
2. The bicycle, as described in paragraph 1, wherein said spring means comprises a first spring assembly proximate to the front road wheel, and second and third spring assemblies proximate to the rear road wheel.
3. The bicycle, as described in paragraph 2, wherein said first spring assembly comprises a tension spring exerting an upward pulling force on said lower frame, and a compression spring exerting an upward pushing force on said lower frame.
4. The bicycle, as described in paragraph 2, wherein each spring assembly has a movement axis; the spring movement axes of the three spring assemblies being parallel.
5. The bicycle, as described in paragraph 2, wherein each spring assembly has a vertical movement axis.
6. The bicycle, as described in paragraph 1, wherein said spring means comprises a first spring assembly proximate to the front road wheel, and second and third spring assemblies proximate to the rear road wheel; said first spring assembly comprising a vertical intermediate cylinder attached to said lower frame, an upper cylinder attached to said upper frame, and a lower cylinder attached to said steering connection; said upper cylinder being slidably telescoped into said vertical intermediate cylinder; and said intermediate cylinder being slidably telescoped into said lower cylinder.
7. The bicycle, as described in paragraph 6, wherein said first spring assembly comprises a compression spring located in said lower cylinder and a tension spring located in said upper cylinder.